Locking device for ladders.



, other alternative posltion, in which the stud member 67- constitues a handle by which the "tending' stud 9, adapted to impinge upon the top of the member 68, forshifting'the plate 28 from the osition shown, to its 30 will rest in the opposite end of-the arouate slot-29, and the stud 34 will then be on the opposite side of the carriage 24 from, its present position. I

I A setting lever 80 pivoted'at 81 to the I base plate 10, and is provided with a stud 82, adapted to impinge upon the edge 28' of the plate 28, when the lower arm of the lever 80 is swung laterally. ,In order to swing the-lever 80, a pull rod 83 is pivotally connected at 84 to the upper arm of the lever 80, and the rod, 83 is extended downward and terminates inra forwardly extending finger piece or handle 83', which extends through a slot 85, in the base plate. The lever 80 is pivotally connected at 86 with a spring 87, secured to theguide member,39, and by means of this spring, the lever 80 and pull rod 83 are returned to their normal positions, as shown; the rod 83' acting as a sto for the stud 82.

n operation, the operator pulls the.-car= riage 24 downward, by means of the strip 38, as described, thereby drawing the catch 41 downward; and, said catch being in engagement with the arm 42 of the left-hand bar 42 (see Fig. 2),-this bar 42 is pulled downward so 'as to swing the bell crank 44 to which it is connected by one of the links 43, so that the other link 43, which is attached to the opposite arm of this bell crank and to the adjacent slide bar 42, draws this adjacent slide bar upward while the beam 25 goes downward, until the'arm 42 of the upwardly moving slide bar is on a higher plane than the upper end (if the beam 25, and the stud 40 clears the lower end of the adjacent tongue. 65, so that the beam 25 is drawn laterally, by means of the plate 28, link 33 and spring 32; so that the stud 40', now registers with the next succeeding slot 64, the movement of the beam 25 having beenarrested in this position by means of o the arm 42 of the contiguous bar 42 upon which it has impinged. Now, as the bell crank 44 was swung on its pivot, by the operation just described, the upper link 55 caused the upper jointed lever to swing on its pivot 57, thereby swinging the arm 58, together with its clamp 63 and the music leaf clamped thereby, through an angle of one hundred and eighty degrees. It will be noted that the member 53 is swung through a considerably less angle than one hundred all of the slots and eighty degrees, but the swing of the member 52 and arm 58 is increased by means of the leverage ained byth'e' pivotal connection at 54 an the stud and slotconnection at 51 and 52 (see Fig. 4). Referri g to the preceding operations, wherein'the stud 40 in registry with thesecond slot, it will be; seen that upon allowing the carriage '24 to ascend, the stud 40 will move up into 5 this second, slot, and the catch 41 will en:

gage with the arm 42 of'the third slide bar 42; so that when the carriage 24 and its adjuncts are againlowered, this third bar 42 will be engaged by the catch 41, so as to rock the bellcrank 45' to which it is con-. 'nected; thereby actuating the second joint ed lever and turning the second music leaf,- in the samemanner that the-first music'leaf was turned. This operation continues until 64 have been entered by the stud 40 and until all of the leaves have been turned, in, which operation all. of the bars 42 have been moved and all of the bell cranks have been swung on their pivots;

provided that there are just four music. leaves to be turned. It will be seen-that as the upper end of thebeam 25 swings right-- ward (see Fig. 2'), its lower end swings leftward, therebydrawing the lower'end of the plate 28 and its stud 79 leftward; so that,

at this stage, when the carriage24 is again drawn downward, the ,stud' 79 will be arrested'by the upper end of the stop 68, and

the plate 28 is thereby swung leftward on its pivot 27 until the stud 30 rests in the right-hand end of the slot 29. n swinging leftward,.the plate 28 carries the rod 33 leftward beyond the pivot 27, so that the upper "end of the beam 25 tends to move leftward, so that when the stud 40 is re.- leased from the right-hand slot 64, it moves into registry with the second slot 64 to the left, and is there arrested by the bar 42 immediately .to' the left thereof, having impinged upon the arm 42 of said bar. Durand its adjuncts have pulled each alternate,

slide bar 42 downward, and thereby caused the other alternate slide bars to move upward, and now, in this return movement of the beam 25 and its 'adjuncts,,the bars that were formerly moved upward are now' pulled (downward, so that the bell=cranks 44 and 45 are moved in the opposite direction, soa's to swing the jointed lovers, the arms 38 and the music sheets in the opposite direction; sothat byseveral rapid oscillations of the'carriage 24-the leaves are quickly returned to their normal position, in case it is desired to play the music over again.

In order thatthe music may be properly supported, I provide a shelf 88, preferably composed of two similar halves, which are provided with ap'ertured ears 89, and

A I IQE.

WILLIAM H. ARNOLD, OF MORNING SUN, IOYVA.

LOCKING DEVICE FOR LADDERS.

Specification of Letters Patent.

Patented J an. 19, 1915.

Application filed August 3, 1914. Serial No. 854,840.

To all whom it may concern Be it known that I, VVILLIAM H. ARNOLD, a citizen of the United States, residing at Morning Sun, in the county of Louisa and tate of Iowa, have invented certain new and useful Improvements in Looking De-v embodies in its preferred form a substan-' tially U-shaped locking rod having its intermediate portion pivotally mounted upon the upper end of the ladder proper adjacent to the pivot of the ladder support, plates pivotally mounted at one of their ends upon the side bars of said support, the extremities of the locking rod being out wardly turned and loosely disposed through the other ends of said plates for engagement with the edges of the side bars of the lad der support, whereby the pivotal or spreading movement of said support with respect to the ladder proper is limited.

The invention has for a further object to provide a locking device for ladders of the above character which may be readily applied to ladders of ordinary construction now in general use, and will admit of the folding of the support with respect to the ladder proper without necessitating the manipulation of the lock in order to release said support for folding movement.

With the above and other objects in view as will become apparent as the description proceeds, the invention consists in certain constructions, combinations and arrangements of the parts that I shall hereinafter fully describe and claim.

For a full understanding of the invention, reference is to be had to the following description and accompanying drawing, in which Figure 1 is a perspective view of a ladder having my improved locking attachment applied thereto; Fig. 2 is a side elevation, the ladder being folded; Fig. 3 is a section taken on the line 33 of Fi g. 2; and Fig. l is a section taken on the line '+l--t of Fig. 2.

Referringin detail to the drawing wherein I have illustrated a very well known construction of step ladder, 5 designates the ladder proper, and 6 the supporting section therefor. The longitudinal side bars 7 of the ladder section and the corresponding bars 8 of the support preferably converge slightly from their lower to their upper ends, the bars of the ladder section being disposed between the side bars of the support at the upper end of the latter and projecting above the same. The support 6 is connected to the ladder proper by means of the pivot bolts 9 so that the ladder 5 may be folded with respect to its support and disposed between the side bars 8 thereof, as shown in Fig. 2. The bars 8 are connected adjacent to their lower ends by means of the brace bar 10.

In the use of the ladder, the support 6 and the ladder 5 are moved in opposite directions or separated in the usual manner so that the ladder proper will be supported in an inclined position. In order to limit this spreading movement of the ladder and its support and obviate collapse of the same, I provide my improved locking device which consists in a U-shaped metal rod 11 of requisite diameter, the intermediate portion of which is pivotally mounted in the eyes 12 fixed in the rear edges of the side bars 7 of the ladder at a point slightly above the pivot bolts 9. The side arms of this U- shaped rod extend in parallel relation to the side bars 8 of the support 6 and have their extremities angularly bent and outwardly extended, as indicated at 13. Metal plates 14: are pivoted at one of their ends, as

shown at 15, upon the inner faces of the bars 8 while the other ends of these plates are provided with openings to loosely receive the out-turned ends 13 of the rod 11. These extremities of the locking rod extend across the rear edges of the bars 8 and are adapted for bearing engagement thereon when the support is separated from the ladder proper, as shown in Fig. 1. It will thus be obvious that the opening or spreading movement of the ladder and its support is limited and the support securely locked against a further outward pivotal movement whereby the complete collapse of the ladder, under a weight imposed thereon, is 

